Brake Light Blinker Does It with Three Fives

Sometimes you use a Raspberry Pi when you really could have gotten by with an Arudino. Sometimes you use an Arduino when maybe an ATtiny45 would have been better. And sometimes, like [Bill]’s motorcycle tail light project, you use exactly the right tool for the job: a 555 timer.

One of the keys of motorcycle safety is visibility. People are often looking for other cars and often “miss” seeing motorcyclists for this reason. Headlight and tail light modulators (circuits that flash your lights continuously) are popular for this reason. Bill decided to roll out his own rather than buy a pre-made tail light flasher so he grabbed a trusty 555 timer and started soldering. His circuit flashes the tail light a specific number of times and then leaves it on (as long as one of the brake levers is depressed) which will definitely help alert other drivers to his presence.

[Bill] mentions that he likes the 555 timer because it’s simple and bulletproof, which is exactly what you’d need on something that will be attached to a motorcycle a be responsible for alerting drivers before they slam into you from behind.

We’d tend to agree with this assessment of the 555; we’ve featured entire 555 circuit contests before. His project also has all of the tools you’ll need to build your own, including the files to have your own PCB made. If you’d like inspiration for ways to improve motorcycle safety in other ways, though, we can suggest a pretty good starting point as well.

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34 thoughts on “Brake Light Blinker Does It with Three Fives”

Having been a rider, I think I’m more alert to motorcyclists than your average cage driver, and I can say that the flash brake light is definitely more noticeable. The modulated headlights also make you a little more noticeable, but as a cage driver, I think they’re distracting in a bad way.

On a variation of this, I built an AVR-based widget that flashed my amateur radio callsign in Morse on the eye-level tail light on my ’03 Jetta when the brakes were first applied, but wouldn’t do it again for either 10 minutes or until two brake applications that lasted longer than 10 seconds.

I actually had the idea for the brake light blinker several years before they released them. I talked about it once in public and less than 6 months later it appeared on the market. I was near a Toyota plant and suspect someone from there was listening.

Not legal in the UK but it doesn’t matter now that the police have only the responsibility for fund raising. I have never seen anyone cautioned for having them on a bicycle and they are illegal on those too. You are not likely to get prosecuted for it.

In a car probably not but in the US depending on your style of Motorcycle sometimes cops take extra interest in you. Especially if you have the misfortune as being on the same road as a group ride that’s been causing trouble.

Not legal in this state. Yet strobing/blinking brakelights are installed on every municipal ambulance and nearly every fire truck because it has been found that they they DO significantly improve safety. However, they are NOT allowed on ambulances owned by private companies.

Tinted windows are also illegal in this state, but the state police purchased a fleet of SUVs as well as many unmarked vehicles and all have DEEPLY tinted windows all the way around.

And, here it seems (may have changed) it is legal for a motorcycle to strobe its headlight during daytime and they are ungoshly irritating and definitely gain your attention, but this is not legal on any other vehicle. And it is often seen that a police vehicle has it’s headlights strobing during an emergency to improve safety.

Certainly does seem like clickbaiting has risen in these parts… How long before the ads start?

Flashing lights have been legal for cyclists since 2005 as the main light
I don’t thinks it’s ever been illegal to have them before that, just not as the main light, there needed to be a constant light with them.

FYI it’s legal in the EU (including UK for now) if set up correctly, but only for hard deceleration. The specific regs at 4Hz +/-1Hz, only triggers if braking from above 50kmph (30mph). You can also have the hazard lights trigger if the hard braking continues below 14kmph (9mph)

Simple and elegant. One question – how to protect the PCB from the elements?

I installed one of those ‘fancy’ units with the accelerometer, but I was hit when stopped, so it didn’t really help. I went back to a commercially available unit that is activated when the brake is applied, similar to this design. That way, I can apply the lights under my control as a car approaches me from behind.

I would really like to have a surface-to-surface, distracted driver seeking missile.

Clicked on your name, and it took me to your website, which indicates that you are in Chalfont. Did you work at Moore Products back in the day? If so, I think that I started a bit after you parted, but I think I may remember seeing your name in comments in the PSC firmware source code. In fact, expanding the ROM space for the PSC using a bank-switching hack of the ROM was one of my better early hacks.

Brake light blinker/strobe hacks should be ILLEGAL. I HATE these things! I live in S.E. Asia and every kid that has a motorcycle or car thinks it is COOL to install a cheap Chinese-made in-line brake light blinker/strobe module (and mod the lights to be blindingly bright too!) The problem is not only the (obvious) confusion with emergency flashers… You should try sitting for hours in a traffic-jam behind some pecker-head that installed a brake light blinker/strobe. I’m tempted to carry a Claw Hammer in my car so I can put these blinker tail-light mods OUT every time I they piss me off! Now I’m seen ultra-bright LED motorcycle headlight mods that strobe all the time. So you get the problem not only from the front, but from your rear-view mirrors as too :-(

Sadly in the US there is almost a total disarray in lighting standards and enforcement. Blinding add on LED’s without focusing just a hemisphere of dazzle mounted lower down in the plastic bumper. Corncob LED’s shoved into halogen headlights that had focus now don’t. LED under lighting uses every colour that first responders use.

No kidding. Aftermarket headlights that run anywhere from pink through blue, usually misaimed. Rednecks with 3′ wide 500K lumen LED light bars on the front of their 4×4 pickups with 12″ lift kits running them while they’re *on road*. Lexuses (Lexusii? What’s plural for Lexus?) with white marker lights on the trunk that lead you to believe they actually have their reverse lights on. Cars with one working brake lamp.

I thought there used to be color temperature standards for headlights and brake lights. Either they don’t actually exist, or they’re not enforced at all.

Small things.
This board is just over a square inch. Usually can’t use somebody else’s board design cause isn’t often you have the same exact component packages and is a pity to wait for mailorder. No way that I’d do this in any CAD, too much time lost but do want a board. Sharpie and some copper clad board is it. Do it all the time. This one would be double-sided too. If making more than 10 just hand draw it on paper and copy or scan it for toner transfer. Little things go a lot faster if the computer is skipped and this one is just such a schematic. Estimate 4 or 5 of these done in an evening. One-of in 45 minutes.

Yep… well I haven’t even bothered to get my boards etched (properly)… you’ll note in the project the board is dead-bugged. The only “etching” I did was using a hacksaw to cut a few pads for +12V, regulated power and a small area for the MOSFET.

Been working reliably that way for about 5 years now.

I could make it smaller using SMD. In fact, since the design is reasonably stable, that is an option, getting some boards etched and using an SOIC NE555.

Also, bicycle lights that blink drive me bonkers, when the light’s off I have no idea where the guy is or where he’s headed, straight into me possibly? What is that anyway? A slow motorcycle? Somebody with a flashlight? Constant on lights already blink and bob from motion…

Now on the other hand, the turn signals on recent mustangs. That is an amazing design. It’s Pretty and gives me insight into what’s happening.

I think brake lights should be made of a light bar that grows as more brake is applied. (or maybe like the horizontal 3rd brake lights one some cars could be used this way). Just a short line shows, I’m nervous and don’t know what I’m doing so I’m keeping my foot rested on the brake. A big line shows, Oh crap I missed that box in the road and my abs engaged.

I got pulled over for having modulated headlights once. Not on purpose, alternator was half hosed and not filtering its output.
Mostly the cop just wanted to check what was going on, just an equipment warning.